JPS5941156A - Brazing method by plating - Google Patents

Abstract

PURPOSE:To improve the fusion-bonding strength without using an expensive silver brazing by plating in advance by tin or zinc the surface of a parent material to be bonded, energizing and heating the part while pressing the part to fusion-bond it. CONSTITUTION:When a flexible connection terminal 2 is connected to the end of a silver bus bar 1, thin copper plates 21 are first silver plated one by one on the surfaces of both ends, and then superposed. The plates are energized and heated while interposing the parts of the both ends between both electrodes 3 and 3' of a carbon resistance welding machine and pressing the parts. When the heating temperature exceeds the melting temperature of the tin, the parts to be bonded of the tin and the copper are formed in bronze and fusion-bonded like hard brazing.

Description

[Detailed Description of the Invention] This invention is a brazing method that does not require the use of expensive brazing filler metal in the work, and provides welding strength equal to or higher than that of hard solder and a high degree of dissolved Ti1S. is about the method.

With the advancement of insulating materials, recent electrical equipment is used with specifications that can withstand high temperatures, such as insulation class F, so instead of soldering, the connection points of conductive parts are hard brazed, which has a high melting heat and a high welding strength. are often adopted. For example, as shown in FIG. 1 (side view) and FIG. 2 (top view), a flexible connection terminal 2 is constructed by assembling a plurality of thin copper plates 21 at the tip of a conductor, that is, a copper busbar 1. When joining, first stack a predetermined number of thin copper plates 22 on top of one another, and tighten the top end of the thin copper plates 22, that is, the side to be connected to the copper bus bar 1 (range of dimension a), and the side where the terminal hole 22 is located (range of dimension A). ) is brazed using hard solder, and then this flexible connection terminal 2 is butted against the tip of the copper bus bar 1 and brazed with hard solder.

However, the above-mentioned brazing method has the disadvantage that manufacturing costs are high due to the extensive use of expensive brazing materials such as silver solder. In addition, when the base material is welded, for example, in a large number of thin plates, it is difficult to raise the temperature of the base material on an average basis, and there is also the disadvantage of work in that part of the base material overheats and the base material melts. Ta.

This invention eliminates the above-mentioned drawbacks, makes brazing work easier even in the case of Pv boards, joins them without using expensive brazing materials, and furthermore, the bath-attached part is equivalent to or better than that of hard brazing. The purpose is to obtain weld strength and melting temperature. In order to achieve this objective, the following methods were adopted. That is, the surfaces of the base materials to be joined were tin-plated or zinc-plated, and then these parts were welded at °C by heating with electricity while pressing them together.

Embodiments of the present invention will be described below based on the drawings. 1st
The figure is a side view of a conductor to which a brazing method using plating, which is an embodiment of the present invention, is applied, and FIG. 2 is a plan view of the same conductor. When connecting the flexible connection terminal 2 to the tip of the copper busbar 1 in the figure, first tin plate (or galvanized) and then layered together. As shown in FIG. 3, the dimension a of both ends is
(or b) Both electrodes 3.3 of the carbon resistance welding machine
’ While pressing with scissors, heat with electricity. At this time, 7lux is applied for deoxidizing, but no brazing filler metal is used for brazing. In this way, when the heating temperature is heated to a high temperature exceeding the melting temperature of tin (or zinc) (e.g., about 800°C), the mating surfaces of the tin and copper at the joint portions of dimensions a and b become bronze (zinc and copper mating surfaces). If it is a surface, it is made of brass)
They are directly attached and integrated as if they were hard-soldered. Next, when welding the tip end surface of the dimension a of this flexible connection terminal 2 to the tip surface of the copper bus bar 1, even if we braze it using hard solder, the welded portion of the dimension a will not be affected by the hard solder. Since it does not melt at the working temperature, the dimension a part is safe and the thin copper machine 2I will not be thrown apart.

Next, FIG. 4 is a 1111 side view showing the connection points between the commutator and armature winding in a DC machine to which the method of brazing combined with plating, which is another embodiment of the present invention, is applied, and FIG. 5 is a sectional view taken along line XX in FIG. 4. FIG.

This is the upper conductor (steel material) 4L of the armature winding, the lower conductor (steel material) 4', and the commutator piece! This structure uses a riser (iron material) to connect to the j. The reason why an iron plate was used instead of a highly conductive material for the riser material is that this part requires appropriate electrical resistance and mechanical strength. Here, upper conductor 4. 7. Use flux at the joint between the lower conductor 4' and the riser 6. ．． 1' The method of coloring is ingenious. This is because even if the flux is removed after brazing, in some cases it may be difficult to remove the flux, and some residual flux may remain there, causing a drop in the insulation of the armature winding insulation near the joint. This is because it has an adverse effect. For this reason, a flux-free copper brazing filler metal may be used, but if a copper brazing filler metal is used, brittle phosphides are formed on the riser (iron material). Phosphorus brazing filler metal cannot be used because the mechanical strength of the welded area is weakened due to the so-called phosphorus brittleness of iron.

Therefore, the following method was adopted for such welding points. First, the copper additional piece 7 is joined to the tip of the riser 6. At this time, the brazing method according to the present invention is applied. That is, the tip of the riser 6 and the copper additional piece 7 are each plated with tin or tin in the same manner as described above, and the plated parts are sandwiched and pressure-welded to the electrodes of a carbon resistance welding machine as shown in Fig. 2, and only flux is applied. If we apply current and heat without using silver solder, welding strength equal to or higher than that of silver solder can be achieved. Next, after sufficiently removing the flux, (
In this case, since the welding location is far from the armature winding, there is no location where it would be difficult to remove 7 lux. ) Attach the upper conductor 4 to this copper additional piece 7. The lower conductor 4' is brazed with phosphor copper solder that does not require flux. In addition, when joining the commutator piece (steel material) 5 and the riser 6, the narrow sling of the commutator piece 5) 51
Although it is difficult to plate the tip of the riser 6 (the part where the 514 pieces enter), it is tin-plated (or zinc-plated) in advance, then inserted into the slit 51, and then welded with a carbon resistance welder. When crimping and heating are carried out, it is difficult for the silver solder to enter the gap between the slit 5 and the riser 6, but the plated tin or zinc acts as the silver solder and the silver solder enters the gap sufficiently. Brazing provides strength.

As mentioned above, the surfaces of the base materials to be joined are coated with tin,
Since the parts plated with zinc or the like are pressed together and welded by heating with electricity, welding strength and melting temperature equal to or higher than those of hard soldering can be obtained without using expensive hard soldering materials such as silver solder. be able to. Furthermore, joining of thin plates can be easily accomplished using this method.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conductive part with a flexible connection piece attached to the tip of a bus bar, Fig. 2 is a plan view of the same conductive part, and Fig. 3 is a brazing by plating which is an embodiment of the present invention. 4 is a side view showing the connection point between the electric commutator and the armature winding in a DC machine, and FIG. FIG. 21.6, 7: Base material (21: thin copper plate, 6: riser, 7
: Copper addition piece.

Claims (1)

[Claims] l) Brazing by plating is a method characterized by applying tin plating or zinc plating to the surfaces of the base materials to be joined in advance, and then welding these parts by applying electricity and heating while pressing them together.